A new success for Leonard makes Sheldon very jealous and throws Penny for a loop. Meanwhile, Koothrappali pushes Lucy too far in their relationship, on the sixth season finale of The Big Bang Theory airing Thursday at 8/7c. On CBS.

This story contains spoilers!

Showrunner Steve Molaro, stars Jim Parsons, Mayim Bialik, Kunal Nayyar and Kate Micucci talk with THR about what’s ahead in the final episode of season six.

CBS’ The Big Bang Theory took two small steps for man and not one but two giant leaps for Sheldon and Raj during Thursday’s penultimate episode of its record-breaking sixth season.

During “The Love Spell Potential,” Sheldon (Jim Parsons) and Amy (Mayim Bialik) were effectively forced to answer the biggest question facing them as a couple: Will they or won’t they? The answer, revealed during a clever game of Dungeons & Dragons, is … maybe, when the neurotic Sheldon reveals to his girlfriend of three years that he hasn’t ruled out turning their relationship intimate.

“They proceed to role play what is essentially their first sexual experience but it is completely asexual at the same time; I love it,” show runner Steve Molaro tells The Hollywood Reporter. “It’s funny, weird, nerdy and touching. It’s a huge step forward and at the same time, it isn’t. I don’t know where they go from here but I know they’re moving forward.”

Meanwhile, the lovelorn Raj (Kunal Nayyar) bailed on the D&D game in favor of another date with the equally damaged Lucy (Kate Micucci) who, after attempting to bail when he pushes her forward faster than she’d like, winds up planting a smooch on her boozed up sweetheart.

“He’s found, as he would say, someone who has even more issues than he does and he thinks that’s very attractive in a woman,” Molaro says. “He’s falling for her. They had this sweet, slow-moving, broken relationship and it’s very nice to see them move forward in it. That kiss was weird, sweet and touching and if you can get all those into one moment, it’s pretty great.”

THR hit the Burbank set of The Big Bang Theory to get the scoop on what the latest developments mean for both Raj and Lucy as well as Sheldon and Amy.

Sheldon and Amy“The writers have managed, with all the characters, to have some severe levels of advancement in character growth with very miniscule movements and this is another example of that,” Parsons says of the sexy scene where his D&D character gets down and dirty with Amy’s gaming character. “What’s changed? In some ways, everything you know about Sheldon you begin to look at differently if he’s actually willing to consider sometime in the near future having a physical relationship with Amy. He’s willing to step over a line that he wouldn’t cross before and engage in this imaginary level of it. He’s decided that this person is important enough to him to try to make a change.”

Bialik, meanwhile, says the episode felt like Amy and Sheldon’s own season finale. “We consummate aspects of our relationship through the language of Dungeons & Dragons and it’s a very intimate scene — like the spanking episode — that felt like a very personal thing in our characters’ relationship being played out publicly,” she notes. “That’s as far as Sheldon can go and it’s very sweet. There are ways that every couple manages the challenges they have and Amy and Sheldon are definitely working it out.” As for whether it will make Amy a big D&D fan going forward, Bialik is fairly confident she’ll be eager to play the RPG again.

Raj and Lucy“When the episode starts and things begin to fall apart, I never thought it was going to end with a kiss through a chain-link fence,” Nayyar says of Raj’s lady lovin’ that comes after he pushed Lucy a bit too hard to take greater strides speak up for herself and send her food back. “There was something very beautiful about that scene — she’s a bird in a cage, almost as in life, and is trapped in this metal cage and Raj has to help her out. Through complete frustrating with trying to help her, they find a vulnerable moment together and kiss. I had chain rust under my nose but it was wonderful.” As for what comes next, Nayyar says Raj is going to want to define their relationship and introduce Lucy to his coupled-up friends — both circumstances that could send Lucy running for the nearest bathroom window. “They haven’t talked about boyfriend-girlfriend yet but a part of him wants to lock it down,” Nayyar says, noting he’s enjoying playing a new side of Raj. “He has really found someone and he really believes that this is his chance for love and he wants to introduce her to his friends, which is getting her in a situation where she’s not comfortable and thus helping her evolve more as a person.”

For her part, Micucci says Lucy’s social anxiety won’t fade away following her kiss with Raj. “If anything, they’ve gotten worse because she’s trying to figure out dealing with a guy,” she says, noting she identifies with her character. “Raj’s understanding of Lucy and her really wanting to make this work with him keeps them going and brings them closer.”

As for what comes next week when TV’s No. 1 scripted comedy wraps its sixth season, Molaro notes the series will feature another game-changing moment as it has so frequently this season with Penny’s profession of love to Leonard, Raj’s kiss and Sheldon and Amy’s intimacy discussion. “There will be a watershed moment at the end for at least one of the characters; there will be a major breakthrough,” he says.

What did you think of Sheldon and Amy — and Raj and Lucy’s — big moments? Do you think there’s a future for both couples? Hit the comments with your thoughts. The Big Bang Theory season finale airs Thursday at 8 p.m. on CBS.

When the girls’ trip to Vegas falls through, the guys invite them to play Dungeons & Dragons, causing Sheldon and Amy’s relationship to take an unexpected turn, on THE BIG BANG THEORY, Thursday, May 9th on the CBS.